No module named 'pkg_resources'

Diffenator doesn't currently run. I tried with Python 3.13 and 3.14.

```sh
% diffenator2
Traceback (most recent call last):
File "venv/bin/diffenator2", line 5, in
from diffenator2.__main__ import main
File "venv/lib/python3.13/site-packages/diffenator2/__init__.py", line 5, in
from diffenator2.renderer import FONT_SIZE
File "venv/lib/python3.13/site-packages/diffenator2/renderer.py", line 14, in
from diffenator2.font import DFont
File "venv/lib/python3.13/site-packages/diffenator2/font.py", line 12, in
from diffenator2.template_elements import CSSFontFace, CSSFontStyle
File "venv/lib/python3.13/site-packages/diffenator2/template_elements.py", line 9, in
from .utils import font_family_name
File "venv/lib/python3.13/site-packages/diffenator2/utils.py", line 18, in
from pkg_resources import resource_filename
ModuleNotFoundError: No module named 'pkg_resources'
```

Should I look at diffenator3 instead already? :)